I woke up this morning to a message from a former student who’d sent me a link to Anne-Marie Slaughter’s cover story in the new Atlantic. If you haven’t seen it yet, it’s a brilliant piece that lays out the reasons why women still can’t have it all — and what we as a society ought to do about it. Within a few hours, links to the story were bouncing around the internet (not to mention my Facebook page) including an excellent recap by HuffPost columnist Lisa Belkin.

Slaughter, who gave up a prestigious State Department post in DC — her dream job, in fact – when she realized her family needed her more, starts the piece by recalling a conversation with a friend where she confessed that, when her time in Washington was up, she was going to “write an op-ed titled ‘Women Can’t Have It All.’” Her friend was horrified:

“You can’t write that,” she said. “You, of all people.” What she meant was that such a statement, coming from a high-profile career woman—a role model—would be a terrible signal to younger generations of women. By the end of the evening, she had talked me out of it, but for the remainder of my stint in Washington, I was increasingly aware that the feminist beliefs on which I had built my entire career were shifting under my feet. I had always assumed that if I could get a foreign-policy job in the State Department or the White House while my party was in power, I would stay the course as long as I had the opportunity to do work I loved. But in January 2011, when my two-year public-service leave from Princeton University was up, I hurried home as fast as I could.

Something struck me when I read the piece and started parsing it out for myself. And that’s whether there’s another question we ought to be asking here. It’s not simply whether we can have it all (like Slaughter, I agree: we can’t, at least given current workplace inequities and societal structures) — but what the pervasiveness of that myth has done to a whole generation of women whose expectations are out of sync with what awaits them out there in the real world.

Back when Undecided was just a twinkle in our eye (fueled, no doubt, by a frosty beer or two after a grueling hike on a hot summer day), the question that kept coming up in that initial bout of brainstorming was whether we as women had been sold a bill of goods. And what we found in the two years of research and interviews that followed was that this idea of having it all, the mantra so many of us assumed was our birthright, had led to a world of grief. Because when you’re led to believe that you can have it all — or worse, that you should have it all — you feel like you’ve done it wrong when things don’t measure up. You are to blame. Somehow, you’ve failed. When the truth is that reality — workplace structures, public policy, the culture itself — has not kept pace with our own expectations.

One of the things that gets lost in the “you go, girl” rhetoric is what economists call opportunity cost. As Stanford economist Myra Strober, who founded Stanford’s Center for Research on Women back in 1972, told us, “If you’re doing A, you can’t be doing B. If you’re playing basketball, you can’t be reading Jane Austen.” In other words, unless and until we can clone ourselves, we’re stuck trying to balance a bunch of trade-offs. Don’t get me wrong: This is not another salvo in the Mommy Wars or a knock on feminism. Or even a suggestion that life choices are an either/or proposition. The point is not that we have to choose between family or career — but that we’re going to have to make peace with the fact that if we want to both raise a kid and run a company, it’s not only going to be hard but there are going to be challenges that are greater than we have been led to believe.

Despite our best intentions, very little in either realm is going to be perfect. We may have to compromise. And when we’re raised to be empowered, to believe that we can have it all, that’s one tough pill to swallow.

It’s a hard lesson, made harder by the fact that there aren’t a lot of role models out there who can show us how to navigate the trade-offs. We were discussing this issue last year on a talk show, in fact, when the host brought up Michelle Obama and Oprah as powerful women who seemed to have it all. And what we said was that in the traditional definition of having it all — fabulous career, fabulous marriage, parenthood — neither qualified: Oprah has no family and Michelle, for obvious reasons, has given up her career. Likewise Hillary Clinton or, for that matter, Sheryl Sandberg. Incredible role models, to be sure. But, in a way, scary ones, too. Because for the for the vast majority of us, despite our own aspirations, if they are held up as the ideal, we are bound to feel that we have fallen short.

One of my senior journalism students this year wrote her capstone on the lack of women atop the corporate ladder and what younger women should do to get there. In reporting the story, she interviewed women in leadership positions across the country, essentially digging for tips that would help her generation make it to the C-suite. What she found, good and bad, was a lot of the stuff we write about here. But the thing that struck me was her solid conviction that, when all was said and done, having it all was indeed a possibility.

Which is, I guess, is the right way to think from inside a college classroom: More power to her for her optimism — and her sincere conviction that her generation will be the one to make things work. But still, the question nags. It’s not whether or not we can have it all — but why we saddle ourselves with the expectation that we should.

Sister, it’s complicated. And the choice may have more than a little bit to do with sexism, according to a new study reported on by Slate.

We’ve heard any number of reasons why women avoid math and science, but as Shankar Vedantam reports in Slate, one thing is not in dispute — the conspicuous absence of the extra X in science and tech jobs (where, ahem, the money often is):

Less than one in five professors of science and math at top research universities in the United States is a woman. The gender distribution of engineers at top Silicon Valley companies is similar to the gender distribution of the audience at your average strip club.

Strip club? Ouch. The piece goes on:

Much has been written about why the number of women in science and math plummets as the intellectual demands in those fields rise with age. We’ve spent years arguing about potential differences in the brains of men and women (courtesy of the controversy spurred five years ago by [former Harvard president Lawrence Summers] former head of President Obama’s National Economic Council), the role of discrimination, and differences between men and women in the way they balance work and home life.

Most Americans believe the doors of opportunity are wide open to careers in science and math, a view that meshes perfectly with John Tierney’s recent argument that worries about sexism are a distraction. (Alison Gopnik recently critiqued Tierney’s claim in Slate.) Anyone can become a scientist or an engineer if she has the necessary interest, determination, and talent. If fewer women than men walk through those doors of opportunity, it has to be because fewer women than men have the necessary interest, determination, and talent. Fewer women than men freely choose to become scientists or engineers.

Freely? The operative word. We’ll go there in a minute. But first, as we reported here last year, at least one study has shown that women avoid math and science, not because they lack the aptitude, but because they don’t feel welcome. It’s called social identity threats. We also relayed a conversation with Stanford economist Myra Strober, founder of Stanford’s Center for Research on Women back in 1972. While emphasizing that the pay gap between men and women has to go — she’s an economist, after all — then said this:

“Opening up and making science and engineering more interesting for women so that they go into those careers is very important. I think you teach it in a different way. First of all, some of these science courses are taught so competitively because they’re trying to winnow out which people are going to get good grades in medical school. Of course, women have gone into medicine. But I think science other than medicine, I think women are poorly represented in those fields. And I think it behooves those fields to figure out how to make those courses more appealing to women. And the workplace, too.”

All of which leads us back to Hamlet’s eternal question by way of that Slate piece, which reports on a new study by Jane Stout, Nilanjana Dasgupta, Matthew Hunsinger, and Melissa A. McManus, Amherst psychologists who found that that when girls and women with an aptitude for science and math nonetheless sidestep those careers, it’s often a subtle form of sexism that’s to blame.

In one part of the study, female science students were asked to take a tough math test. They were greeted by volunteers — male or female math majors — and guess what happened? The students who were greeted by women attempted more questions on the test than the students who were greeted by men. In another experiment, the psychologist measured whether having male or female math professors made a difference with female students. It did. When the professor was female, class participation rose from 7 percent at the beginning of the semester to 46 percent by the end. (With male professors? It stayed the same.) Worse, the percentage of students seeking help outside of class dropped from 12 percent at the beginning of the quarter to zero when the prof was a male. With women profs? The percentage rose slightly.

But most important was this:

… when Stout and Dasgupta evaluated how much the students identified with mathematics, they found that women ended up with less confidence in their mathematical abilities when their teachers were men rather than women. This happened even when women outperformed men on actual tests of math performance.

You don’t have to be a science geek to know where this is headed: the subtle discrimination that impacts our choices. And part of that discrimination — let’s just call it sexism — may have to do with whether or not we have role modes who look like us who make us feel that we belong. Back to Slate:

Our reasons for feeling suited to particular professions are only partially—and perhaps tangentially—tied to our interests, determination, and talent. More than three decades ago, psychotherapists at Georgia State University studied why some women, by all objective measures bright and talented, believed they were less gifted than they were. No matter the evidence, they believed they were imposters.

So we’re going to put two and two together here, draw on some other stuff, come up with five. Or maybe three. Who knows. It’s all about the math. Or maybe not. But it’s important. There’s even a treat at the end.

Anyway.

Last week, the San Jose Mercury — located as it is in the heart of Silicon Valley — had a front page biz story on the lack of the XX chromosome in the tech field. Specifically, when it comes to being an entrepreneur. Reporter Scott Duke Harris starts by recalling meeting Jessica Mah, a 17 year old whiz-girl at a TechCrunch gathering three years ago. When she was 13, she had started a Web-hosting service. (Hello, I’m not ever sure what that means.) Now she’s 20, and she has a degree in computer science from UC-Berkeley, has funding from a start-up incubator, and is co founder of a Web-based money management service for small businesses. And what she tells Harris is that despite the fact that her business is doing well, she wonders whether she is a good entrepreneur — or she is benefiting from a good market. WTF. She’s 20 years old. About the same age as that other kid was when he started Facebook.

Let’s read what Harris has to say:

Today, I have another notion about my initial skepticism: Gender profiling. If this had been a geek named Jesse, not Jessica, maybe I’d be wondering if this kid might be the next Zuckerberg, instead of wondering whether to take him seriously.

With former Silicon Valley CEOs Meg Whitman and Carly Fiorina now running self-financed campaigns for higher office and Carol Bartz leading Yahoo, there is less talk today about the “glass ceiling.” But they prospered on the executive track, not as entrepreneurs. While dozens of valley startups have been launched by women — Judy Estrin, Kim Polese and Caterina Fake come to mind — hundreds have been launched by men.

Consider Y Combinator: Since its startup “boot camp” began in 2005, providing techies with shoestring budgets and a collaborative environment, about 450 people have been accepted to the program. The number of women: 14, including Mah and three others in the current class.

It’s tempting to think the Y in Y Combinator has something to do with the Y chromosome. But the name actually derives from a calculus term familiar to geeks. And geeks, it seems, disproportionately happen to have the male XY chromosome, not the female XX. The question is: Why?

Well, I’d beg to differ about what he says about the glass ceiling, and, okay, I don’t like either Whitman or Fiorina, but that’s beside the point. (And if you’ve been living under a rock, Zuckerberg is the kid who started Facebook) So first, I’m pissed. But then I wonder, too: nature or nurture, as Harris asks. Former Harvard president Larry Summers implied it might be nature — and lost his job because of it (though he landed on his feet in the Obama administration.) And we have suggested here that maybe it has to do with women just not being welcome at the party.

Recently, we interviewed Stanford economist Myra Strober, founder of Stanford’s Center for Research on Women back in 1972, for our book. We were talking about the strides women have made since the days when she started her career and became a pretty big name in women’s rights — and where we still need to go. The first thing she said was that the pay gap had to go. She’s an economist, after all.

Second, though, and actually related to her first point, was this: “Opening up and making science and engineering more interesting for women so that they go into those careers is very important. I think you teach it in a different way. First of all, some of these science courses are taught so competitively because they’re trying to winnow out which people are going to get good grades in medical school. Of course, women have gone into medicine. But I think science other than medicine, I think women are poorly represented in those fields. And I think it behooves those fields to figure out how to make those courses more appealing to women. And the workplace, too.”

No kidding. But back to Harris, who at this point in his story, is interviewing Adora Cheung, the 26-year-old founder of another tech start-up:

Cheung suggested that it may be a matter of social expectations: When math gets tough, girls are often told that’s OK and try something else, but boys are encouraged to work harder.

Cheung said she was pleasantly surprised to find three other women in her Y Combinator class. Contagion Health co-founder Jen McCabe, who has scant computing skills, teamed with an engineer on their startup, designed to use social networks to promote healthy living. The notion that Y Combinator discriminates, McCabe said, is preposterous: “I’m actually surprised more women don’t do this.”

And after talking to the women of Y Combinator — and thinking about my young daughter and her brothers — I’m thinking that Cheung is on to something. Maybe the paucity of female tech entrepreneurs has something to do with what has been called the soft bigotry of low expectations.

Ya think? And now, I’m kinda bummed that I never stuck it out as a math major. Not that I necessarily wanted to go into that field as a career. But it would have given me some street cred to call out the likes of Larry Summers.

On the other hand — and here’s the toy in the Crackerjacks box — I never would have related to the Mad Men job interview. Apparently, I’d make a good Accounts Manager.